Gear-shift mechanism



F. CONRAD.

GEAR SHIFT MECHANISM.

APPLICATION FILED JAN- 30. I914. RENEWED MAY 18. 19I8.

I 1,363,719. Patented Dec. 28,1920.

3 SHEETSSHEET I- 42a 2 O O INVENTOR ""W WITN E SSES:

E CONRAD. GEAR SHIIFT MECHANISM.

APPHCATION FHED IAN-30,1914. RENEWED MAY 18.19I&

1,363,719. v Patented Dec. 28, 1920.

3 SHEETS-SHEET 3- INVENTOR MW ATTORNEY my invention attached thereto.

UNITED STATES PATENT OFFICE.

FRANK CONRAD, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGH U E ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

GEAR-SHIFT MECHANISM.

Application filed January 30, 1914, Serial No. 815,366.

To all whom it may concern:

Be it known that l, FRANK CONRAD, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Gear-Shift Mechanism, of which the following is a specification.

My invention relates to gear shift mechanisms for automobiles or other motor vehicles, and it relates particularly to such mechanisms as are controlled by selective devices and are actuated by pedals or levers that are usually employed in the control of such vehicles.

My invention has for its object to provide a device of the character above indicated that is simple in construction and effective in operation under all circumstances.

A second object of my invention is to provide a locking device for automatically preventing the actuation of the gear shift mechanism except under predetermined conditions.

In the operation of a gear shift mechanism that is controlled or actuated by a lever or pedal the normal function of which is to control other parts of the motor vehicle, as, for example, the clutch pedal, it is essential that the normal operation of the pedal shall not affect the position of the shift mechanism. It is also essential that the pedal effect the proper changes in the transmission mechanism, when desired. without requiring the operator, by a separate act, to release a locking or safety device which may be employed to prevent an inadvertent actuation of the shift mechanism.

I have provided a safety device which, during the normal operation of the clutch pedal. limits its path of movement to such an extent that the shifting mechanism is not actuated. \Vhen the controlling m chanism is set for any desired change in the position of the gear wheels, the safety device is automatically rendered ineffective and the clutch pedal may then actuate the shifting mechanism without obstruction.

In the accompanying drawings, Figure l is a view. partially in plan and partially in section, of a portion of an automobile with l ig. 2 is a view, partially in elevation and partially in section, of the transmission mechanism of an automobile and its related parts. Fig. 3

Specification of Letters Patent.

Patented Dec. 28, 1920.

Renewed May 18, 1918. Serial No. 235,888.

is a plan view of the gear shifting mechanism. Fig. at is a view, in longitudinal section, of the mechanism of Fig. Figs. and G are views of details. Fig. 7 is a sectional view of the mechanismof Fig.3. Fig. 8 1s a view, in section, on line VIII-VIII of Fig. 3. Fig. 9 is a diagrammatic view of the electrical circuits employed in connection with my invention and of the mechanism for controlling a set of push buttons that control the circuits.

Referring particularly to 11 igs. 1 and 2, an automobile chassis 1, only a portion of which is shown, is .)rovided with a gas engine 2 having a fly wheel A transmission mechanism or change-speed gear mechanism 4 is connected to the engine 2 by a shaft 5 and a conical clutch member 6 that is slidably mounted on the shaft 5 to coact with a correspondingly shaped clutch member 7 formed in the fly wheel The clutch member 6 is provided with an integral grooved collar 8 to be engaged by a yoke member 9 that has a pivotal support upon a bracket 10. A pedal 11, that is adapted to be operated by the foot of the operator, has a pivotal support upon a lug 12 and is connected by a link 13 to the yoke member 9. A spring 14, that is attached at one end to a suitable stationary part, normally retains the clutch pedal 11 in its rearward position with the clutch member (3 engaging the fly wheel 3. The clutch pedal 11 is provided with an extended portion 15 that is connected by a link 16 to a gear shifting mechanism indi eated broadly at 17. y

The transmission mechanism it forms no part of my invention but is combined therewith, so that a description thereof is, accordingly, desirable in order to explain the operation of the gear shifting mechanism. The shaft which is connected to the clutch member 6, extends into the transmission casing'ld through an end wall 19 and has a hearing therein. A gear wheel 20, having two sets of gear teeth 21 and 22, is mounted. upon the shaft 5 within the casing 18. A transmission shaft 23, which is connected to the main transmission shaft 24, is in axial alinement with the shaft 5 and has a hearing at 25 within the gear wheel 20. The shaft 23 is adapted to be connected to the shaft 5 at different speed ratios by means of two gear wheels 26 and 27 that are slidably keyed upon the shaft 23, ear wheels 28, 29, 30 and 31 that are fixed upon a counter shaft 32 and an idler gear wheel 28 that is in mesh with the gear wheel 28.

The gear wheel 31 is always in mesh with the gear gear teeth 22 to establish a fixed speed ratio between the shafts and The mechanism is arranged to provide three speeds in the forward and one in the reverse direction. The changes in speed ratio are controlled by the slidable gear wheels 26 and. 27 which are respectively provided with integral grooved collars 33 and 3 1 to be engaged by yoke members 35 and The yoke members 35 and are respectively fixed upon shift rods and 38 that are controlled by the gear shifting mechanism, as will he later described.

lVhen the gear wheel. 26 is in mesh with the gear wheel 29, the mech: nism is in its first or low-speed position anu the shaft 5 is connected through the gear teeth 22, gear wheel 31, counter shaft 52 and gear wheels an 1 26 to the transmission shaft For the second or intermediate speed, the gear wheel 27 is shifted into mesh with the gear wheel For the third or high speed, the gear wheel 27 is shifted to tl e right until internal gear teeth 39, with which the gear wheel 2? is provided, mesh with the teeth The shaft 5 is then directly connected to the transmission shaft 23 and the latter is driven at engine speed. For driving in the reverse direction, the wheel 26 is shifted into mesh with the idler wheel 28' which is always in mesh with t. gear wheel 28. The transmission mechanism is illustrated in its neutral or inoperative position in which the shaft 23 is not connected to the counter shaft 32.

Referring now to Figs. to 8, inclusive, the gear shifting mechanism comprises a housing or casing 19 having end we 45.1. which provide bearings for two s i and, 4:3. The shift rods 42 and 4-3, i slidable axially in t eir hearings, its tively connected to the shift rods 37 and of the transmission mechanism. Two blocks ll and 15 are slidabiy mounted upon the shift rods 42 and 13. The blocks n and are connected by links d6 to the oppositely extending arms of a lever l7. The oscillation of the lever d7 operates to slide the blocks l4 and 45 in opposite directions simultaneously. The lever 4:7 is fixed upon a rock shaft 48 that is provided with a cranlr arm 4&8". The crank arm 4E8 has a pin and slot connection with the link to permit independent movement of the latter to shift the clutch into and out of engagen'tent.

The shift rods d2 and each provided with longitudinal groove having elined shoulder portions 59 at each end. Dogs 51, that are pivotally mounted on opposite sides of the blocks 4-; and are provided with horizontally extending arms 52 having hook portions Normally, the arms 02 are retained by springs 52 in the pr f ions shown in Fig. 1, with the hook portions 53 resting upon the bottom of the grooves 49 in position to engage the shoulder portions 50. The dogs 51 are also provided ith. arms 54 that extend substantially vertically and are each provided with a horizontally extending portion 55.

Four stationary solenoids, or electromag nets of the clapper type 90, 91, 92 and 93 are attached to the side walls of the housing to, each of the solenoids being adjacent one of the corners of the housing. The solenoids comprise coils 94, 95, 96 and 97, respectively. Each solenoid comprises, also, an armature 56 having a pivotal support indicated at 57 and normally held outward by a spring Each armature 56 is provided, upon its outer face, with a stop 59 of substantially U-shape. lVhen the solenoids are deinergized, the vertical portions 60 of the corresponding stops are in the paths of movement of the arms of the coacting dogs 51, and the vertical portions 61 of the said stops are in the paths movement of lugs 62.

The lugs 62, which are four in numl'e are located on the under sides of the Sllll' rods 12 and &3, there being one on each upon each side of the hioc s lll When the blocks 4st and 4-5 are ll'lOv wardly, and the arms 54: are engaged the respective stops 59, the dogs 51 are rocked on their pivots and the arms 52 are raised upwardly from the grooves &9 so that the hook portions 53 cannot engage the shoulder portions 50. When one of the lugs 62 engages the corresponding stop 59, further movement of the corresponding shift rod in that direction is prevented.

When the solenoids are energized, the an matures are drawn inwardly and the stops 59 do not obstruct the outward movements of the several arms 5d and the lugs 62. The arms 54 then pass between the vertical portions 60 and 61 of the stops 59, the horizontal portions 55 of the arms being of suiiicient length to retain the armatures in this position until the arms 54 are withdrawn. In the operation of the mechanism, which is later described, it is possible to energize only one of the solenoids at one time. Consequently, if one of the solenoids be energized, all of the arms 52 except that one corresponding to the energized solenoid will be raised to prevent the respective hook p0rtions 53 from engaging the shoulder portions 59 with which they coact. The arm 52 that is not raised will engage its coacting shoulder portion 50 and a further movement of the sliding blocks 4 1 and l5 will cause a shifting of the rod 42 or 4:3, as the case may be, to shift the one or the other of the slidable gear wheels 26 and 27 in the same direction. Each of four self-closing limit switches (53, which are mounted in pairs in each end of the casing 40, comprises a movable member 6 1 having a pin 05 to project into a groove 06 in the rod 12 or 13, as the case may be. The pin 65 is actuated by a coacting shoulder portion 6'7 to open its corresponding limit switch when the shift rod has reached the limit of its endwise movement. Each limit switch 03 controls the circuit of one of the solenoids, the arrangement being such that the circuit of the solenoid that has been energized to cause the shifting of one of the rods 42 and 13, when the blocks 4st and 45 are actuated in opposite directions, is always broken by the corresponding limit switch that is opened at the end of the movement of the said rod which causes meshing ot the transmission gear wheels.

The movement oi the pedal 11 beyond its clutch disengaging position, and the consequent actuation of the block members as. and 4.5 to return the shifted gear wheel to its neutral position, is controlled by a solenoid 68 that is attached to a side wall 09 of the housing 40. The solenoid GS is provided with an armature 70 having a pivotal support at 71. The armature 70 is provided with a stop member 72 to coact with a pin 73 that is fixed to the block member 14;. When the solenoid 68 is dcenergized, a spring 741 holds the armature '70 in its outer position, with the stop member 72 in engagement with the pin 73. Vhen the solenoid 68 is ener gized, the armature 70 is drawn inwardly against the tension of the spring 7 1 to with draw the stop member 72 from the path of movement of the pin 73. The clutch pedal may then be moved freely to actuate the block members 44 and 15 to shift the gear wheels, as desired.

The electrical circuits for controlling the gear shitting mechanism are illustrated in Fig. 9. The electrical connections comprise five parallel circuits which are respectively controlled by push buttons 77, 78, T9, 80 and 81. The several push buttons are designated according to the speed ratio controlled by them as 3rd, 2nd, 1st, N (neutral), and R (reverse), respectively. The push buttons 77, 78, 79 and 81 are so interlocked that only one button can be actuated at one time and this one remains closed until another button has been actuated. The button 80, or neutral button, is arranged to open as soon as released after actuation. The solenoid coils 9 1, 95, 96 and 97 are in series with the push buttons 77 78, 79 and 81, respectively, and with the corresponding limit switches (33. The winding 7 5 of the solenoid 68 is in series with each of the parallel circuits and with a 1 battery 83,

at my invention. llach plltill button, except the neutral button 90, is provided with a head portion 90 having a notch or groove 99 to be engaged by coacting portions 100 of a sprii'ig pressed slidablc member 101 when the button has been depressed to bring tl e groove 99 into register with the corresponding Jortion 100. The several push buttons comprise inclined portions 102 and reduced portions 103 which project downwardly through slots 101 in the member 101, and are provided with lugs or bosses 105. The lugs 105 are wedge-shaped at one end to be inserted between the ends of bars 106 that are slidably mounted between two suitable stationary parts 107 and 108. The distance between the stationary parts 10'? and 108 is equal to the sum of the lengths oi the several bars 100 and. the width of one of the lugs 105, thereby insuring that only one of the push buttons may be fully depressed at one time. ll' hen one of the buttons is depressed, the lug 105 is inserted between the ends Oi the correspoi'iding bars 106 and the groove 99 is engx god by the coacting portion 100 to loci; it in its depressed position, with the correspondingcontact members 109 en-- gage-d. lVhen it is desired to close a second circuit, "the corresponding button is pressed, and the inclined portion 102 engages the locking portion 100 to slide the member 101 to the left and thereby release the first push button before the lug 105 has engaged the corresponding bars 106. The neutral button 80, which is not provided with a groove 99, operates to release any other button which may have been locked in position to close its co esponding circuit.

' it may be assun'ied that the transmission gearing is in its nez'itral position, as .illus trated in F 2, and that the gear shitting mechanism is in it": corresponding normal or 118l1t111l position, as shown in Figs. 3 am 1. lit may be assumed, also, that the engine has been started and that the engine clutch members 0 and 7 are disengaged. It is de- Si- .ble to it the vehicle on first speed. and the pi button 79 s accordingly pressed to close a circuit from the battery through the push Y itton '79. coil 98 of the solenoid 9E2, limit switch 02:3 and solenoid coil 7:") to the battery. The coil 96 is energized to draw the armature 50 ot the solenoid 99 inwardly so that it cannot obstruct the movement of the corresponding dog 51 and lug 02. The coil of the solenoid (l3 is also energized to draw the armature l0 7 inwardly to ca se the stop member to release the pin. he clutch pedal 11, which. at the time of starting the engine, is in such a position that the engine clutch members 0 and are in engagement, then pressed forwardly beyond the clutch-oisengaging position. The linl: 10 then rotates the reel; shalt by means of the crank arm 48, and

actuate the hool: por tiens 53 of the arms Slit ing along the grooves 49. When the hook portions 58 appramch the shoulders 50, the arms 54:, with the exception of that one coacting with the solenoid 92, engage the corresponding stops 59, and the dogs 51 are rocked about their pivots to raise the arms 52 from the grooves 49. Further movement of the blocks causes the dog 51 that is not rocked to engage the rod 42 and move it to the right, (Figs. 3 and 4-.) to mesh the gear wheel 26 with the gear wheel 29.

hen the gear wheels 26 and 29 are fully meshed, the shoulder portion 67 and the pin (55 will have opened the corresponding limit switch 63 to break the circuit comprising the coil 96 and the coil 75. The operator then allows the spring 1% to retract the clutch pedal 11. A spring 76 that is attached at one end to a stationary rug 76 and at the other end to the lever 1 returns tl blocks and. to their respective normal positions. The several dogs 51 are thus re turned to their respective normal posi ions, the springs 52 drawing the arms downwardly as soon as the hook portions have passed'the shoulders 50. The engine clutch is still out when the various parts are in their respective normal or neutral positions. liurther return movement of the clutch i lal will effect the engagement of the enclutch, and the vehicle will be driven through the conn ctions above described.

The circuit controlled ly the push button 79 will remain open until another button 18 been pressed and the gears shifted from e first-speed position. The limit switch 40 will remain open until the shift rod 42 has been returned to witl'idraw the shoulder 67 from engagement with the pin 65. The coil 75 cannot be energized until a push button other than 79 is pressed. it is, therefore, impossible to actuate the lever d7 of the shifting mechanism by means of the clutch pedal 11 before a second button has been actuated. The clutch can be controlled as desired without in any way affect 1g the transmission gear mechanism, the pin and slot connection permitting the necessary independent movement of the pedal 11.

When it is desired to change the speed ratio, as, for example, to second speed, the push button 78 may be pressed at any time desired in advance of the actual change. The coil 95 of the solenoid 91 and the coil 75 will be energized to perform the same functions as described in connection with the corresponding parts when the push button 79 was closed. To eflect the change to the desired speed, the operator presses the pedal 11 to disengage the engine clutch. The rod 42 is in its shifted position and the these parts to engage.

shoulder 50 at the left end of the groove 49 is near the coacting hook portion 53 of the adjacent arm 52 so that a slight outward movement of the latter member will cause The further actuation of the pedal 11 after the clutch is out, therefore, first operates to shift the rod 42 to its neutral position. At this point, all of the dogs 51 except that one controlled by the solenoid 91 have engaged their corresponding coacting stops 59, and the arms 52 are rocked out of engagement with the respective shoulders 50. But, since the coil 95 of the solenoid 91 is energized, the coacting dog is still in operative position, and the further movement of the clutch pedal 11 causes the rod l3 to be shifted to the left and the gear wheel 27 to be shifted into mesh with the gear wheel 30. The coacting limit switch 63 will then be opened and the coils 95 and 75 deenergized. The release of the penal 1.1 first causes the blocks 44: and 45 and the dogs 51 to be returned to their respective normal positions by the spring 76, whereupon the stop member 72 again engages the pin 73. The further movement of the pedal by the spring 14 effects the enement of the engine clutch, and the veliic will be driven at second speed. In the same manner, changes may be made to third speed or the direction of drive reversed by actuating the appropriate push buttons 77 and 81, respectively. It will, of course be understood that, in order to reverse the direction of the vehicle, it is necessary to bring it to a stop before the clutch is thrown in.

lVhen it is desired to return either of the shiftable gear wheels 26 and 27 to the neutral position, the neutral button 80 is closed to energize the coil 75. This action may occur regardless of the closure of any of the speed-controlling buttons 77, 78, 79 and 81. The clutch is disengaged as before, whereupon the lever el'? is actuated by the rock shaft 48 to shift the blocks 44C and 45 outwardly. The shifted rod is in a position to be engaged immediately by the appropriate dog 51 to return it to its normal or neutral position. When the dogs 51 reach the stops 59, all of the arms 52 are rocked out of the grooves 49, since none of the controlling solenoids 90, 91, 92 and 93 are energized. It is then impossible to shift the gear wheels until one of the buttons, other than the neutral button 80, is closed.

It will be noted that I have provided mechanism which operates automatically to limit the movement of the clutch pedal except under predetermined conditions. hen the operator has adjusted the controlling mechanism to select another gear wheel to be shifted, the locking device is automatically withdrawn, and additional movement of the clutch pedal is thus permitted in order that the change in gear ratio may be effected.

I claim as my invention:

1. In a gear shifting mechanism, the com: bination with a shiftable member, and an actuating member connected thereto, oi

means for selectively controlling the actua tion of said shiftable member, and means controlled by said controlling means for limiting the path of movement of said actuating member.

2. In a gear shifting mechanism, the combination with a shiftable member, and a pedal connected thereto, of means for selectively controlling the direction of move ment of said shiftable member, and means controlled by said controlling means for limiting the path of movement of said pedal.

In a gear shifting mechanism, the combination with a shiftable member, a clutch, and a lever arranged to control the clutch and the shiftable member during separate portions of its path of movement, of means for selectively controlling the actuation of said shiftable member, and means controlled by said controlling means for limiting the path of movement of said lever to the clutch controlling portion.

4. In a gear shifting mechanism, the combination with a movable member, and an actuating member connected thereto, oi electro-responsive means for selectively controlling said movable member, and for controlling the path of movement of said actuating member.

5. In a gear shifting mechanism, the combination with a movable member, and an actuating member connected thereto, of a stop tor obstructing the movement or said actuating member, and means for simultaneously controlling said stop and the direction oi movement of said movable member.

6. In a gear shifting mechanism, the combination with a shii'table member, and means for actuating the same, of electro-responsive means for selectively controlling the direction of movement of said shit'table member and for preventing actuation of said shiltable member except when said direction of movement has been selected.

7. In a gear shifting mechanism, the combination with a shiftable mcmber,oi means for shifting said member in opposite directions, means comprising an electromagnet for selectively controlling the direction 0t movement of said member, and means comprising an electromagnet electrically connected to the other electromagnet for preventing said movcment except under predetermined conditions.

8. In a gearshifting mechanism,the com bination with a shiitable member, of means for actuating the same, and interlocked electromagnetic devices for selectively con trolling the actuation of the shift-able mem her and the direction of movement of the same.

In testimony whereof, I have hereunto subscribed my name this 24th day of Jan,

FRANK CONRAD. lVitnesses VILLIAM BRADSHAW, B. B. HINEs. 

